The aim of this study is to evaluate the toxicity and tolerance of carbon ion radiotherapy for recurrent pancreatic carcinoma post surgery

The carbon dose of 67.5 Gy equivalent in 15 fractions was delivered to clinical target volume (CTV). The dose limiting toxicity (DLT) was defined as CTCAE grade 3 or higher of non-hematological toxicity (G3). The acute and late toxicities, overall survival (OS), progression-free survival (PFS), local progression-free survival (LPFS) and distant metastasis-free survival (DMFS) were the endpoints.

Inclusion Criteria:

1. The histologically or cytologically confirmed pancreatic adenocarcinoma;
2. Local-regional recurrent pancreatic cancer post surgery, no evidence of distant metastases, based upon Positron Emission Tomography, CT, or MRI images of the chest, abdomen and pelvis within 30 days prior to registration;
3. Eastern Cooperative Oncology Group Performance Status 0-1 within 30 days prior to registration;
4. Age of ≥ 18 years old;
5. Enough hematological function (white blood cell count ≥ 3.0×109/L; platelets ≥50×109/L; hemoglobin ≥ 90 g/L);
6. Enough liver and kidney functions (creatinine <110gmol/L; urea nitrogen <7.1mmol/L; bilirubin < 1.5 x ULN, alanine aminotransferase and aspartate aminotransferase ≤ 2.5 x ULN);
7. Informed consent form obtained.

Exclusion Criteria:

1. Eastern Cooperative Oncology Group Performance Status >=2；
2. Liver, kidney and bone marrow function are poor and not adequate for treatment;
3. GI was invaded by recurrent lesions;
4. Prior radiation therapy to the abdomen or radioactive particle implantation or other local treatment for the recurrent lesions;
5. Cardiac pacemaker or other metal implantation whose function may be disturbed by high energy beam or which affect the dose in target volume;
6. Dose constrain of normal liver, digested system and other organ at risk could not reach the expecting safe dose constrain;
7. The patient could not get benefit from proton or heavy ion radiotherapy in physician's opinion;
8. Comitant diseases which could affect the proton or heavy ion radiotherapy;
9. Pregnancy（blood or urine β-human chorionic gonadotropin certified）or lactation;
10. Drug or alcohol abused;
11. HIV positive, including received anti-retrovirus treatment; chronic hepatitis B virus replication stage; hepatitis C active stage; syphilis active stage;
12. hepatitis B virus positive, hepatitis B virus replication stage, need to be treated with anti-virus treatment, but could not receive anti-virus treatment because of comitant disease;
13. Psychiatric history, possibly affecting the completion of treatment;
14. Patients with serious complications that might affect radiotherapy， including 1）unstable angina pectoris requiring hospitalization in the last 6 months，congestive heart failure，myocardial infarction； 2）acute bacterial or systemic fungal infections； 3）exacerbation of chronic obstructive pulmonary disease ( COPD) or other respiratory system disease requiring hospitalization 4）hepatic function insufficiency or renal function insufficiency 5） immunosuppressed patients
15. patients with connective tissue disease such as active scleroderma or lupus and so on, which is contraindication for radiotherapy
16. patients can't understand treatment goal or unwilling/unable to sign up inform consent form；
17. no civil capability or limited civil capacity.